Perhaps the best that can be said for the years-in-the-works "Men in Black 3" is that its prolonged, difficult development rarely leaves visible scars on the finished product.

Perhaps the best that can be said for the years-in-the-works “Men in Black 3″ is that its prolonged, difficult development rarely leaves visible scars on the finished product. This is no small compliment, as subjecting the franchise’s zippy cornball energy to committee rethink and patchwork solutions could have been toxic, and the sequel survives with the original’s spirit largely intact. Pic does betray a few saggy, sloppy edges, and reigniting interest in the property may be a difficult task, but overseas B.O. and franchise newcomer Josh Brolin’s quietly hilarious performance should give it a decent shot.

There are a number of conflicting points to consider in assessing the pic’s commercial potential. In Will Smith, it toplines one of the biggest movie stars on the planet, albeit one who hasn’t made a single film in four years. Moreover, the film is part of a property that grossed more than $350 million at the U.S. box office alone, yet 10 years have passed since the last installment — the limp “Men in Black II” — and it’s unclear just how strong the interest is for an encore.

But that’s all ultimately a problem for Sony’s marketing department. For their parts, director Barry Sonnenfeld and scripter Etan Cohen approach the material in a strangely low-key manner, as though this were merely a midseason episode of a long-running series, rather than a comeback after a decade away. This serves the movie well, however, as it’s clear the filmmakers aren’t simply expecting to coast on audience goodwill.

Oddly enough, the film seems to anticipate audience fatigue with its characters early on. After a prologue in which shotglass-eyed baddie Boris the Animal (“Flight of the Conchords'” Jermaine Clement) is broken out of a lunar prison, Men in Black partners Agent J (Smith) and Agent K (Tommy Lee Jones) are seen back on Earth, going through the motions of brokering peace among New York City’s undercover alien population and “neuralyzing” eyewitnesses with sub-Bondian one-liners.

Jones is as laconic as always, though even Smith seems notably dialed down this time, with his bellows maintaining an inside-voice volume and his eyebrows rarely extending past half-arch. The conversational rhythms between the two partners have slowed, and J begins to interrogate K about his continued reticence to open up to him, even after 15 years of working together. The funereal mood then culminates in an actual funeral.

Then, just as one has begun to wonder where all this ennui and Oedipal anxiety is heading, escaped alien Boris travels back in time to 1969 — when the young Agent K initially foiled his evil scheme, leading to Boris’ imprisonment — and kills the intergalactic lawman, with Agent J the only one who notices something is wrong in the present day. With Boris’ evil brethren now angling for planet-wide invasion, J must travel back to the summer of ’69 himself to protect his young partner (now played by Brolin), and put Boris down for good.

Most time-travel plots reveal holes upon later reflection, but this one is so openly nonsensical, with its own rules so arbitrarily applied, that scrutiny is a killjoy. This may rub some auds the wrong way, though “Men in Black 3″ is at its best when it simply owns its own absurdity. (At one point, we learn that ruptures in the space-time continuum cause headaches, which in turn produce a powerful craving for chocolate milk.)

Now back in New York of the ’60s, Smith’s J serves as the straight man for some expectedly groanable time-period gags, though there are thankfully fewer of these than one might initially fear. (A trip to Andy Warhol’s Factory in search of aliens is too obvious by half, though Bill Hader’s turn as Warhol goes a long way toward justifying it.)

Fortunately, J isn’t stranded too long before running into Brolin’s young Agent K, at which point the pic perks up noticeably. Brolin puts in a performance of almost eerie verisimilitude (indeed, there are brief shots where one almost suspects Jones has served as Brolin’s stand-in), nailing Jones’ Texas drawl and granite facial tics while subtly suggesting a childlike spirit hidden beneath. The pic never overdoes the character’s youthfulness, of course; casting a 44-year-old thesp to play K at age 29 is one of its better in-jokes.

Aside from Brolin’s K, the pic introduces a delightfully Vonnegutian new character in Michael Stuhlbarg’s Griffin, a weirdly adorable humanlike creature who can see all possible outcomes of any given scenario. (His description of the wild combination of variables that had to line up to allow the Miracle Mets’ victorious ’69 season is the closest this series has ever veered toward poetry.) That this creature is forced to serve as conduit for the film’s undeservedly sappy ending may cut down his overall grade, but he reps a nice addition nonetheless.

As in the past editions, Rick Baker’s alien character designs and makeup remain a high point, and an early shootout in a Chinese restaurant may be the sickest and stickiest sequence in the series’ history. Sonnenfeld endeavors to keep a light touch amid the serviceable 3D mayhem, and aside from some weirdly dodgy effects work in seemingly straightforward shots — a glimpse of the partners riding together in a car has the cutout roughness of an old “Dragnet” episode — the big moments come off swimmingly. Time-traveling sequences and a climatic battle that takes notes from “Casino Royale’s” best setpiece are particularly well executed.

In this age of blockbuster bloat, Sonnenfeld’s willingness to wrap things up well before the two-hour mark, as well as his eschewal of sledgehammer product placement, count as gestures of considerable mercy.

Men in Black 3

Production

A Sony Pictures Entertainment release of a Columbia Pictures presentation in association with Hemisphere Media Capital of an Amblin Entertainment production in association with Parkes/MacDonald Imagenation. Produced by Walter F. Parkes, Laurie MacDonald. Executive producers, Steven Spielberg, G. Mac Brown. Directed by Barry Sonnenfeld. Screenplay, Etan Cohen, based on the Malibu Comic by Lowell Cunningham.